<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<style>			
			.a{
				display: flex;
				margin: 90px auto;
				width: 60%;
				background-color: white;
				height: 500px;
				border: 1px solid black;
				justify-content: center;
				align-items: center;
			}
			.b{
				background-color: red;
				display: flex;
				flex-basis: 200px;
				height: 121.35px;
				
			}
			
		</style>
	</head>
	<body>

			<div class="a">
				<div class="b"></div>
				<div class="b"></div>
				<div class="b"></div>
				<div class="b"></div>
			</div>
		
	</body>
</html>